diff --git a/Lib/base64.py b/Lib/base64.py
index 18beffc..fc05ea9 100755
--- a/Lib/base64.py
+++ b/Lib/base64.py
@@ -27,13 +27,13 @@
     ]
 
 
-bytes_buffer = (bytes, buffer)  # Types acceptable as binary data
+bytes_types = (bytes, bytearray)  # Types acceptable as binary data
 
 
 def _translate(s, altchars):
-    if not isinstance(s, bytes_buffer):
+    if not isinstance(s, bytes_types):
         raise TypeError("expected bytes, not %s" % s.__class__.__name__)
-    translation = buffer(range(256))
+    translation = bytearray(range(256))
     for k, v in altchars.items():
         translation[ord(k)] = v[0]
     return s.translate(translation)
@@ -52,12 +52,12 @@
 
     The encoded byte string is returned.
     """
-    if not isinstance(s, bytes_buffer):
+    if not isinstance(s, bytes_types):
         s = bytes(s, "ascii")
     # Strip off the trailing newline
     encoded = binascii.b2a_base64(s)[:-1]
     if altchars is not None:
-        if not isinstance(altchars, bytes_buffer):
+        if not isinstance(altchars, bytes_types):
             altchars = bytes(altchars, "ascii")
         assert len(altchars) == 2, repr(altchars)
         return _translate(encoded, {'+': altchars[0:1], '/': altchars[1:2]})
@@ -75,10 +75,10 @@
     s were incorrectly padded or if there are non-alphabet characters
     present in the string.
     """
-    if not isinstance(s, bytes_buffer):
+    if not isinstance(s, bytes_types):
         s = bytes(s)
     if altchars is not None:
-        if not isinstance(altchars, bytes_buffer):
+        if not isinstance(altchars, bytes_types):
             altchars = bytes(altchars, "ascii")
         assert len(altchars) == 2, repr(altchars)
         s = _translate(s, {chr(altchars[0]): b'+', chr(altchars[1]): b'/'})
@@ -147,7 +147,7 @@
 
     s is the byte string to encode.  The encoded byte string is returned.
     """
-    if not isinstance(s, bytes_buffer):
+    if not isinstance(s, bytes_types):
         s = bytes(s)
     quanta, leftover = divmod(len(s), 5)
     # Pad the last quantum with zero bits if necessary
@@ -204,7 +204,7 @@
     the input is incorrectly padded or if there are non-alphabet
     characters present in the input.
     """
-    if not isinstance(s, bytes_buffer):
+    if not isinstance(s, bytes_types):
         s = bytes(s)
     quanta, leftover = divmod(len(s), 8)
     if leftover:
@@ -213,7 +213,7 @@
     # False, or the character to map the digit 1 (one) to.  It should be
     # either L (el) or I (eye).
     if map01:
-        if not isinstance(map01, bytes_buffer):
+        if not isinstance(map01, bytes_types):
             map01 = bytes(map01)
         assert len(map01) == 1, repr(map01)
         s = _translate(s, {b'0': b'O', b'1': map01})
@@ -283,7 +283,7 @@
     s were incorrectly padded or if there are non-alphabet characters
     present in the string.
     """
-    if not isinstance(s, bytes_buffer):
+    if not isinstance(s, bytes_types):
         s = bytes(s)
     if casefold:
         s = s.upper()
@@ -330,7 +330,7 @@
 
     Argument and return value are bytes.
     """
-    if not isinstance(s, bytes_buffer):
+    if not isinstance(s, bytes_types):
         raise TypeError("expected bytes, not %s" % s.__class__.__name__)
     pieces = []
     for i in range(0, len(s), MAXBINSIZE):
@@ -344,7 +344,7 @@
 
     Argument and return value are bytes.
     """
-    if not isinstance(s, bytes_buffer):
+    if not isinstance(s, bytes_types):
         raise TypeError("expected bytes, not %s" % s.__class__.__name__)
     return binascii.a2b_base64(s)
 
diff --git a/Lib/dumbdbm.py b/Lib/dumbdbm.py
index 78e4999..7741fbb 100644
--- a/Lib/dumbdbm.py
+++ b/Lib/dumbdbm.py
@@ -163,7 +163,7 @@
         if not isinstance(key, bytes):
             raise TypeError("keys must be bytes")
         key = key.decode("latin-1") # hashable bytes
-        if not isinstance(val, (buffer, bytes)):
+        if not isinstance(val, (bytes, bytearray)):
             raise TypeError("values must be byte strings")
         if key not in self._index:
             self._addkey(key, self._addval(val))
diff --git a/Lib/encodings/idna.py b/Lib/encodings/idna.py
index 30f507a..c2ba1da 100644
--- a/Lib/encodings/idna.py
+++ b/Lib/encodings/idna.py
@@ -153,7 +153,7 @@
         if not input:
             return b'', 0
 
-        result = buffer()
+        result = bytearray()
         labels = dots.split(input)
         if labels and not labels[-1]:
             trailing_dot = b'.'
@@ -216,7 +216,7 @@
                 if labels:
                     trailing_dot = b'.'
 
-        result = buffer()
+        result = bytearray()
         size = 0
         for label in labels:
             if size:
diff --git a/Lib/encodings/punycode.py b/Lib/encodings/punycode.py
index 56e6958..b801a46 100644
--- a/Lib/encodings/punycode.py
+++ b/Lib/encodings/punycode.py
@@ -10,7 +10,7 @@
 
 def segregate(str):
     """3.1 Basic code point segregation"""
-    base = buffer()
+    base = bytearray()
     extended = set()
     for c in str:
         if ord(c) < 128:
@@ -78,7 +78,7 @@
 digits = b"abcdefghijklmnopqrstuvwxyz0123456789"
 def generate_generalized_integer(N, bias):
     """3.3 Generalized variable-length integers"""
-    result = buffer()
+    result = bytearray()
     j = 0
     while 1:
         t = T(j, bias)
@@ -107,7 +107,7 @@
 def generate_integers(baselen, deltas):
     """3.4 Bias adaptation"""
     # Punycode parameters: initial bias = 72, damp = 700, skew = 38
-    result = buffer()
+    result = bytearray()
     bias = 72
     for points, delta in enumerate(deltas):
         s = generate_generalized_integer(delta, bias)
diff --git a/Lib/io.py b/Lib/io.py
index 364e6d0..f66f48b 100644
--- a/Lib/io.py
+++ b/Lib/io.py
@@ -391,7 +391,7 @@
                 return 1
         if limit is None:
             limit = -1
-        res = buffer()
+        res = bytearray()
         while limit < 0 or len(res) < limit:
             b = self.read(nreadahead())
             if not b:
@@ -454,14 +454,14 @@
             n = -1
         if n < 0:
             return self.readall()
-        b = buffer(n.__index__())
+        b = bytearray(n.__index__())
         n = self.readinto(b)
         del b[n:]
         return bytes(b)
 
     def readall(self):
         """readall() -> bytes.  Read until EOF, using multiple read() call."""
-        res = buffer()
+        res = bytearray()
         while True:
             data = self.read(DEFAULT_BUFFER_SIZE)
             if not data:
@@ -655,7 +655,7 @@
     # XXX More docs
 
     def __init__(self, initial_bytes=None):
-        buf = buffer()
+        buf = bytearray()
         if initial_bytes is not None:
             buf += initial_bytes
         self._buffer = buf
@@ -823,7 +823,7 @@
         self.max_buffer_size = (2*buffer_size
                                 if max_buffer_size is None
                                 else max_buffer_size)
-        self._write_buf = buffer()
+        self._write_buf = bytearray()
 
     def write(self, b):
         if self.closed:
@@ -1276,7 +1276,7 @@
         try:
             decoder.setstate((b"", decoder_state))
             n = 0
-            bb = buffer(1)
+            bb = bytearray(1)
             for i, bb[0] in enumerate(readahead):
                 n += len(decoder.decode(bb))
                 if n >= needed:
diff --git a/Lib/pickle.py b/Lib/pickle.py
index d7bf24e..e3c112f 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -39,7 +39,7 @@
            "Unpickler", "dump", "dumps", "load", "loads"]
 
 # Shortcut for use in isinstance testing
-bytes_types = (bytes, buffer, memoryview)
+bytes_types = (bytes, bytearray, memoryview)
 
 # These are purely informational; no code uses these.
 format_version = "2.0"                  # File format version we write
diff --git a/Lib/plat-mac/aepack.py b/Lib/plat-mac/aepack.py
index e958b85..5f8efd2 100644
--- a/Lib/plat-mac/aepack.py
+++ b/Lib/plat-mac/aepack.py
@@ -98,7 +98,7 @@
         return AE.AECreateDesc(b'long', struct.pack('l', x))
     if isinstance(x, float):
         return AE.AECreateDesc(b'doub', struct.pack('d', x))
-    if isinstance(x, (bytes, buffer)):
+    if isinstance(x, (bytes, bytearray)):
         return AE.AECreateDesc(b'TEXT', x)
     if isinstance(x, str):
         # See http://developer.apple.com/documentation/Carbon/Reference/Apple_Event_Manager/Reference/reference.html#//apple_ref/doc/constant_group/typeUnicodeText
diff --git a/Lib/plat-mac/aetypes.py b/Lib/plat-mac/aetypes.py
index d29ea97..6c031a1 100644
--- a/Lib/plat-mac/aetypes.py
+++ b/Lib/plat-mac/aetypes.py
@@ -22,7 +22,7 @@
     four_chars must contain only ASCII characters.
 
     """
-    if isinstance(four_chars, (bytes, buffer)):
+    if isinstance(four_chars, (bytes, bytearray)):
         b = bytes(four_chars[:4])
         n = len(b)
         if n < 4:
diff --git a/Lib/string.py b/Lib/string.py
index 6117ac0..7f67abd 100644
--- a/Lib/string.py
+++ b/Lib/string.py
@@ -53,7 +53,7 @@
         raise ValueError("maketrans arguments must have same length")
     if not (isinstance(frm, bytes) and isinstance(to, bytes)):
         raise TypeError("maketrans arguments must be bytes objects")
-    L = buffer(range(256))
+    L = bytearray(range(256))
     for i, c in enumerate(frm):
         L[c] = to[i]
     return bytes(L)
diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index aef8f94..23252f4 100644
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -222,7 +222,7 @@
             # this could raise OverflowError.
             n = struct.unpack("L", struct.pack("l", n))[0]
 
-        s = buffer()
+        s = bytearray()
         for i in range(digits - 1):
             s.insert(0, n & 0o377)
             n >>= 8
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index 116145e..e9285a6 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -532,8 +532,8 @@
 
         # XXX Commented out. Is there any reason to support buffer objects
         # as arguments for str.replace()?  GvR
-##         ba = buffer('a')
-##         bb = buffer('b')
+##         ba = bytearray('a')
+##         bb = bytearray('b')
 ##         EQ("bbc", "abc", "replace", ba, bb)
 ##         EQ("aac", "abc", "replace", bb, ba)
 
diff --git a/Lib/test/test_audioop.py b/Lib/test/test_audioop.py
index fada40c..ffb1cd5 100644
--- a/Lib/test/test_audioop.py
+++ b/Lib/test/test_audioop.py
@@ -87,7 +87,7 @@
         print('add')
     data2 = []
     for d in data:
-        str = buffer(len(d))
+        str = bytearray(len(d))
         for i,b in enumerate(d):
             str[i] = 2*b
         data2.append(str)
@@ -177,7 +177,7 @@
         print('mul')
     data2 = []
     for d in data:
-        str = buffer(len(d))
+        str = bytearray(len(d))
         for i,b in enumerate(d):
             str[i] = 2*b
         data2.append(str)
@@ -207,7 +207,7 @@
 def testtomono(data):
     if verbose:
         print('tomono')
-    data2 = buffer()
+    data2 = bytearray()
     for d in data[0]:
         data2.append(d)
         data2.append(d)
@@ -218,7 +218,7 @@
 def testtostereo(data):
     if verbose:
         print('tostereo')
-    data2 = buffer()
+    data2 = bytearray()
     for d in data[0]:
         data2.append(d)
         data2.append(d)
diff --git a/Lib/test/test_binascii.py b/Lib/test/test_binascii.py
index fa13563..fb9a666 100755
--- a/Lib/test/test_binascii.py
+++ b/Lib/test/test_binascii.py
@@ -56,7 +56,7 @@
             a = binascii.b2a_base64(b)
             lines.append(a)
 
-        fillers = buffer()
+        fillers = bytearray()
         valid = b"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+/"
         for i in range(256):
             if i not in valid:
@@ -64,7 +64,7 @@
         def addnoise(line):
             noise = fillers
             ratio = len(line) // len(noise)
-            res = buffer()
+            res = bytearray()
             while line and noise:
                 if len(line) // len(noise) > ratio:
                     c, line = line[0], line[1:]
@@ -72,7 +72,7 @@
                     c, noise = noise[0], noise[1:]
                 res.append(c)
             return res + noise + line
-        res = buffer()
+        res = bytearray()
         for line in map(addnoise, lines):
             b = binascii.a2b_base64(line)
             res += b
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index b3c13b3..5c3a3ae 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -1,4 +1,4 @@
-"""Unit tests for the bytes and buffer types.
+"""Unit tests for the bytes and bytearray types.
 
 XXX This is a mess.  Common tests should be moved to buffer_tests.py,
 which itself ought to be unified with string_tests.py (and the latter
@@ -27,12 +27,12 @@
         warnings.filters = self.warning_filters
 
     def test_basics(self):
-        b = buffer()
-        self.assertEqual(type(b), buffer)
-        self.assertEqual(b.__class__, buffer)
+        b = bytearray()
+        self.assertEqual(type(b), bytearray)
+        self.assertEqual(b.__class__, bytearray)
 
     def test_empty_sequence(self):
-        b = buffer()
+        b = bytearray()
         self.assertEqual(len(b), 0)
         self.assertRaises(IndexError, lambda: b[0])
         self.assertRaises(IndexError, lambda: b[1])
@@ -48,7 +48,7 @@
 
     def test_from_list(self):
         ints = list(range(256))
-        b = buffer(i for i in ints)
+        b = bytearray(i for i in ints)
         self.assertEqual(len(b), 256)
         self.assertEqual(list(b), ints)
 
@@ -58,57 +58,57 @@
                 self.i = i
             def __index__(self):
                 return self.i
-        b = buffer([C(), C(1), C(254), C(255)])
+        b = bytearray([C(), C(1), C(254), C(255)])
         self.assertEqual(list(b), [0, 1, 254, 255])
-        self.assertRaises(ValueError, buffer, [C(-1)])
-        self.assertRaises(ValueError, buffer, [C(256)])
+        self.assertRaises(ValueError, bytearray, [C(-1)])
+        self.assertRaises(ValueError, bytearray, [C(256)])
 
     def test_from_ssize(self):
-        self.assertEqual(buffer(0), b'')
-        self.assertEqual(buffer(1), b'\x00')
-        self.assertEqual(buffer(5), b'\x00\x00\x00\x00\x00')
-        self.assertRaises(ValueError, buffer, -1)
+        self.assertEqual(bytearray(0), b'')
+        self.assertEqual(bytearray(1), b'\x00')
+        self.assertEqual(bytearray(5), b'\x00\x00\x00\x00\x00')
+        self.assertRaises(ValueError, bytearray, -1)
 
-        self.assertEqual(buffer('0', 'ascii'), b'0')
-        self.assertEqual(buffer(b'0'), b'0')
+        self.assertEqual(bytearray('0', 'ascii'), b'0')
+        self.assertEqual(bytearray(b'0'), b'0')
 
     def test_constructor_type_errors(self):
-        self.assertRaises(TypeError, buffer, 0.0)
+        self.assertRaises(TypeError, bytearray, 0.0)
         class C:
             pass
-        self.assertRaises(TypeError, buffer, ["0"])
-        self.assertRaises(TypeError, buffer, [0.0])
-        self.assertRaises(TypeError, buffer, [None])
-        self.assertRaises(TypeError, buffer, [C()])
+        self.assertRaises(TypeError, bytearray, ["0"])
+        self.assertRaises(TypeError, bytearray, [0.0])
+        self.assertRaises(TypeError, bytearray, [None])
+        self.assertRaises(TypeError, bytearray, [C()])
 
     def test_constructor_value_errors(self):
-        self.assertRaises(ValueError, buffer, [-1])
-        self.assertRaises(ValueError, buffer, [-sys.maxint])
-        self.assertRaises(ValueError, buffer, [-sys.maxint-1])
-        self.assertRaises(ValueError, buffer, [-sys.maxint-2])
-        self.assertRaises(ValueError, buffer, [-10**100])
-        self.assertRaises(ValueError, buffer, [256])
-        self.assertRaises(ValueError, buffer, [257])
-        self.assertRaises(ValueError, buffer, [sys.maxint])
-        self.assertRaises(ValueError, buffer, [sys.maxint+1])
-        self.assertRaises(ValueError, buffer, [10**100])
+        self.assertRaises(ValueError, bytearray, [-1])
+        self.assertRaises(ValueError, bytearray, [-sys.maxint])
+        self.assertRaises(ValueError, bytearray, [-sys.maxint-1])
+        self.assertRaises(ValueError, bytearray, [-sys.maxint-2])
+        self.assertRaises(ValueError, bytearray, [-10**100])
+        self.assertRaises(ValueError, bytearray, [256])
+        self.assertRaises(ValueError, bytearray, [257])
+        self.assertRaises(ValueError, bytearray, [sys.maxint])
+        self.assertRaises(ValueError, bytearray, [sys.maxint+1])
+        self.assertRaises(ValueError, bytearray, [10**100])
 
     def test_repr_str(self):
         warnings.simplefilter('ignore', BytesWarning)
         for f in str, repr:
-            self.assertEqual(f(buffer()), "buffer(b'')")
-            self.assertEqual(f(buffer([0])), "buffer(b'\\x00')")
-            self.assertEqual(f(buffer([0, 1, 254, 255])),
-                             "buffer(b'\\x00\\x01\\xfe\\xff')")
+            self.assertEqual(f(bytearray()), "bytearray(b'')")
+            self.assertEqual(f(bytearray([0])), "bytearray(b'\\x00')")
+            self.assertEqual(f(bytearray([0, 1, 254, 255])),
+                             "bytearray(b'\\x00\\x01\\xfe\\xff')")
             self.assertEqual(f(b"abc"), "b'abc'")
             self.assertEqual(f(b"'"), '''b"'"''')
             self.assertEqual(f(b"'\""), r"""b'\'"'""")
 
 
     def test_compare(self):
-        b1 = buffer([1, 2, 3])
-        b2 = buffer([1, 2, 3])
-        b3 = buffer([1, 3])
+        b1 = bytearray([1, 2, 3])
+        b2 = bytearray([1, 2, 3])
+        b3 = bytearray([1, 3])
 
         self.assertEqual(b1, b2)
         self.failUnless(b2 != b3)
@@ -128,7 +128,7 @@
         self.failIf(b3 <  b2)
         self.failIf(b3 <= b2)
 
-    def test_compare_bytes_to_buffer(self):
+    def test_compare_bytes_to_bytearray(self):
         self.assertEqual(b"abc" == bytes(b"abc"), True)
         self.assertEqual(b"ab" != bytes(b"abc"), True)
         self.assertEqual(b"ab" <= bytes(b"abc"), True)
@@ -165,19 +165,19 @@
         self.assertEqual(b"\0\0\0a\0\0\0b\0\0\0c" == "abc", False)
         self.assertEqual(b"a\0b\0c\0" == "abc", False)
         self.assertEqual(b"a\0\0\0b\0\0\0c\0\0\0" == "abc", False)
-        self.assertEqual(buffer() == str(), False)
-        self.assertEqual(buffer() != str(), True)
+        self.assertEqual(bytearray() == str(), False)
+        self.assertEqual(bytearray() != str(), True)
 
     def test_nohash(self):
-        self.assertRaises(TypeError, hash, buffer())
+        self.assertRaises(TypeError, hash, bytearray())
 
     def test_doc(self):
-        self.failUnless(buffer.__doc__ != None)
-        self.failUnless(buffer.__doc__.startswith("buffer("), buffer.__doc__)
+        self.failUnless(bytearray.__doc__ != None)
+        self.failUnless(bytearray.__doc__.startswith("bytearray("), bytearray.__doc__)
         self.failUnless(bytes.__doc__ != None)
         self.failUnless(bytes.__doc__.startswith("bytes("), bytes.__doc__)
 
-    def test_buffer_api(self):
+    def test_bytearray_api(self):
         short_sample = b"Hello world\n"
         sample = short_sample + b"\0"*(20 - len(short_sample))
         tfn = tempfile.mktemp()
@@ -187,7 +187,7 @@
                 f.write(short_sample)
             # Test readinto
             with open(tfn, "rb") as f:
-                b = buffer(20)
+                b = bytearray(20)
                 n = f.readinto(b)
             self.assertEqual(n, len(short_sample))
             self.assertEqual(list(b), list(sample))
@@ -205,25 +205,25 @@
 
     def test_reversed(self):
         input = list(map(ord, "Hello"))
-        b = buffer(input)
+        b = bytearray(input)
         output = list(reversed(b))
         input.reverse()
         self.assertEqual(output, input)
 
     def test_reverse(self):
-        b = buffer(b'hello')
+        b = bytearray(b'hello')
         self.assertEqual(b.reverse(), None)
         self.assertEqual(b, b'olleh')
-        b = buffer(b'hello1') # test even number of items
+        b = bytearray(b'hello1') # test even number of items
         b.reverse()
         self.assertEqual(b, b'1olleh')
-        b = buffer()
+        b = bytearray()
         b.reverse()
         self.assertFalse(b)
 
     def test_getslice(self):
         def by(s):
-            return buffer(map(ord, s))
+            return bytearray(map(ord, s))
         b = by("Hello, world")
 
         self.assertEqual(b[:5], by("Hello"))
@@ -244,33 +244,33 @@
     def test_extended_getslice(self):
         # Test extended slicing by comparing with list slicing.
         L = list(range(255))
-        b = buffer(L)
+        b = bytearray(L)
         indices = (0, None, 1, 3, 19, 100, -1, -2, -31, -100)
         for start in indices:
             for stop in indices:
                 # Skip step 0 (invalid)
                 for step in indices[1:]:
-                    self.assertEqual(b[start:stop:step], buffer(L[start:stop:step]))
+                    self.assertEqual(b[start:stop:step], bytearray(L[start:stop:step]))
 
     def test_regexps(self):
         def by(s):
-            return buffer(map(ord, s))
+            return bytearray(map(ord, s))
         b = by("Hello, world")
         self.assertEqual(re.findall(r"\w+", b), [by("Hello"), by("world")])
 
     def test_setitem(self):
-        b = buffer([1, 2, 3])
+        b = bytearray([1, 2, 3])
         b[1] = 100
-        self.assertEqual(b, buffer([1, 100, 3]))
+        self.assertEqual(b, bytearray([1, 100, 3]))
         b[-1] = 200
-        self.assertEqual(b, buffer([1, 100, 200]))
+        self.assertEqual(b, bytearray([1, 100, 200]))
         class C:
             def __init__(self, i=0):
                 self.i = i
             def __index__(self):
                 return self.i
         b[0] = C(10)
-        self.assertEqual(b, buffer([10, 100, 200]))
+        self.assertEqual(b, bytearray([10, 100, 200]))
         try:
             b[3] = 0
             self.fail("Didn't raise IndexError")
@@ -298,35 +298,35 @@
             pass
 
     def test_delitem(self):
-        b = buffer(range(10))
+        b = bytearray(range(10))
         del b[0]
-        self.assertEqual(b, buffer(range(1, 10)))
+        self.assertEqual(b, bytearray(range(1, 10)))
         del b[-1]
-        self.assertEqual(b, buffer(range(1, 9)))
+        self.assertEqual(b, bytearray(range(1, 9)))
         del b[4]
-        self.assertEqual(b, buffer([1, 2, 3, 4, 6, 7, 8]))
+        self.assertEqual(b, bytearray([1, 2, 3, 4, 6, 7, 8]))
 
     def test_setslice(self):
-        b = buffer(range(10))
+        b = bytearray(range(10))
         self.assertEqual(list(b), list(range(10)))
 
-        b[0:5] = buffer([1, 1, 1, 1, 1])
-        self.assertEqual(b, buffer([1, 1, 1, 1, 1, 5, 6, 7, 8, 9]))
+        b[0:5] = bytearray([1, 1, 1, 1, 1])
+        self.assertEqual(b, bytearray([1, 1, 1, 1, 1, 5, 6, 7, 8, 9]))
 
         del b[0:-5]
-        self.assertEqual(b, buffer([5, 6, 7, 8, 9]))
+        self.assertEqual(b, bytearray([5, 6, 7, 8, 9]))
 
-        b[0:0] = buffer([0, 1, 2, 3, 4])
-        self.assertEqual(b, buffer(range(10)))
+        b[0:0] = bytearray([0, 1, 2, 3, 4])
+        self.assertEqual(b, bytearray(range(10)))
 
-        b[-7:-3] = buffer([100, 101])
-        self.assertEqual(b, buffer([0, 1, 2, 100, 101, 7, 8, 9]))
+        b[-7:-3] = bytearray([100, 101])
+        self.assertEqual(b, bytearray([0, 1, 2, 100, 101, 7, 8, 9]))
 
         b[3:5] = [3, 4, 5, 6]
-        self.assertEqual(b, buffer(range(10)))
+        self.assertEqual(b, bytearray(range(10)))
 
         b[3:0] = [42, 42, 42]
-        self.assertEqual(b, buffer([0, 1, 2, 42, 42, 42, 3, 4, 5, 6, 7, 8, 9]))
+        self.assertEqual(b, bytearray([0, 1, 2, 42, 42, 42, 3, 4, 5, 6, 7, 8, 9]))
 
     def test_extended_set_del_slice(self):
         indices = (0, None, 1, 3, 19, 300, -1, -2, -31, -300)
@@ -335,50 +335,50 @@
                 # Skip invalid step 0
                 for step in indices[1:]:
                     L = list(range(255))
-                    b = buffer(L)
+                    b = bytearray(L)
                     # Make sure we have a slice of exactly the right length,
                     # but with different data.
                     data = L[start:stop:step]
                     data.reverse()
                     L[start:stop:step] = data
                     b[start:stop:step] = data
-                    self.assertEquals(b, buffer(L))
+                    self.assertEquals(b, bytearray(L))
 
                     del L[start:stop:step]
                     del b[start:stop:step]
-                    self.assertEquals(b, buffer(L))
+                    self.assertEquals(b, bytearray(L))
 
     def test_setslice_trap(self):
         # This test verifies that we correctly handle assigning self
         # to a slice of self (the old Lambert Meertens trap).
-        b = buffer(range(256))
+        b = bytearray(range(256))
         b[8:] = b
-        self.assertEqual(b, buffer(list(range(8)) + list(range(256))))
+        self.assertEqual(b, bytearray(list(range(8)) + list(range(256))))
 
     def test_encoding(self):
         sample = "Hello world\n\u1234\u5678\u9abc\udef0"
         for enc in ("utf8", "utf16"):
-            b = buffer(sample, enc)
-            self.assertEqual(b, buffer(sample.encode(enc)))
-        self.assertRaises(UnicodeEncodeError, buffer, sample, "latin1")
-        b = buffer(sample, "latin1", "ignore")
-        self.assertEqual(b, buffer(sample[:-4], "utf-8"))
+            b = bytearray(sample, enc)
+            self.assertEqual(b, bytearray(sample.encode(enc)))
+        self.assertRaises(UnicodeEncodeError, bytearray, sample, "latin1")
+        b = bytearray(sample, "latin1", "ignore")
+        self.assertEqual(b, bytearray(sample[:-4], "utf-8"))
 
     def test_decode(self):
         sample = "Hello world\n\u1234\u5678\u9abc\def0\def0"
         for enc in ("utf8", "utf16"):
-            b = buffer(sample, enc)
+            b = bytearray(sample, enc)
             self.assertEqual(b.decode(enc), sample)
         sample = "Hello world\n\x80\x81\xfe\xff"
-        b = buffer(sample, "latin1")
+        b = bytearray(sample, "latin1")
         self.assertRaises(UnicodeDecodeError, b.decode, "utf8")
         self.assertEqual(b.decode("utf8", "ignore"), "Hello world\n")
 
-    def test_from_buffer(self):
+    def test_from_bytearray(self):
         sample = bytes(b"Hello world\n\x80\x81\xfe\xff")
         buf = memoryview(sample)
-        b = buffer(buf)
-        self.assertEqual(b, buffer(sample))
+        b = bytearray(buf)
+        self.assertEqual(b, bytearray(sample))
 
     def test_to_str(self):
         warnings.simplefilter('ignore', BytesWarning)
@@ -387,12 +387,12 @@
         self.assertEqual(str(b'\x80'), "b'\\x80'")
 
     def test_from_int(self):
-        b = buffer(0)
-        self.assertEqual(b, buffer())
-        b = buffer(10)
-        self.assertEqual(b, buffer([0]*10))
-        b = buffer(10000)
-        self.assertEqual(b, buffer([0]*10000))
+        b = bytearray(0)
+        self.assertEqual(b, bytearray())
+        b = bytearray(10)
+        self.assertEqual(b, bytearray([0]*10))
+        b = bytearray(10000)
+        self.assertEqual(b, bytearray([0]*10000))
 
     def test_concat(self):
         b1 = b"abc"
@@ -404,21 +404,21 @@
         self.assertRaises(TypeError, lambda: "abc" + b2)
 
     def test_repeat(self):
-        for b in b"abc", buffer(b"abc"):
+        for b in b"abc", bytearray(b"abc"):
             self.assertEqual(b * 3, b"abcabcabc")
             self.assertEqual(b * 0, b"")
             self.assertEqual(b * -1, b"")
             self.assertRaises(TypeError, lambda: b * 3.14)
             self.assertRaises(TypeError, lambda: 3.14 * b)
-            # XXX Shouldn't bytes and buffer agree on what to raise?
+            # XXX Shouldn't bytes and bytearray agree on what to raise?
             self.assertRaises((OverflowError, MemoryError),
                               lambda: b * sys.maxint)
 
     def test_repeat_1char(self):
-        self.assertEqual(b'x'*100, buffer([ord('x')]*100))
+        self.assertEqual(b'x'*100, bytearray([ord('x')]*100))
 
     def test_iconcat(self):
-        b = buffer(b"abc")
+        b = bytearray(b"abc")
         b1 = b
         b += b"def"
         self.assertEqual(b, b"abcdef")
@@ -434,7 +434,7 @@
             self.fail("bytes += unicode didn't raise TypeError")
 
     def test_irepeat(self):
-        b = buffer(b"abc")
+        b = bytearray(b"abc")
         b1 = b
         b *= 3
         self.assertEqual(b, b"abcabcabc")
@@ -442,7 +442,7 @@
         self.failUnless(b is b1)
 
     def test_irepeat_1char(self):
-        b = buffer(b"x")
+        b = bytearray(b"x")
         b1 = b
         b *= 100
         self.assertEqual(b, b"x"*100)
@@ -450,7 +450,7 @@
         self.failUnless(b is b1)
 
     def test_contains(self):
-        for b in b"abc", buffer(b"abc"):
+        for b in b"abc", bytearray(b"abc"):
             self.failUnless(ord('a') in b)
             self.failUnless(int(ord('a')) in b)
             self.failIf(200 in b)
@@ -460,7 +460,7 @@
             self.assertRaises(TypeError, lambda: None in b)
             self.assertRaises(TypeError, lambda: float(ord('a')) in b)
             self.assertRaises(TypeError, lambda: "a" in b)
-            for f in bytes, buffer:
+            for f in bytes, bytearray:
                 self.failUnless(f(b"") in b)
                 self.failUnless(f(b"a") in b)
                 self.failUnless(f(b"b") in b)
@@ -474,7 +474,7 @@
                 self.failIf(f(b"abd") in b)
 
     def test_alloc(self):
-        b = buffer()
+        b = bytearray()
         alloc = b.__alloc__()
         self.assert_(alloc >= 0)
         seq = [alloc]
@@ -486,19 +486,19 @@
                 seq.append(alloc)
 
     def test_fromhex(self):
-        self.assertRaises(TypeError, buffer.fromhex)
-        self.assertRaises(TypeError, buffer.fromhex, 1)
-        self.assertEquals(buffer.fromhex(''), buffer())
-        b = buffer([0x1a, 0x2b, 0x30])
-        self.assertEquals(buffer.fromhex('1a2B30'), b)
-        self.assertEquals(buffer.fromhex('  1A 2B  30   '), b)
-        self.assertEquals(buffer.fromhex('0000'), b'\0\0')
-        self.assertRaises(TypeError, buffer.fromhex, b'1B')
-        self.assertRaises(ValueError, buffer.fromhex, 'a')
-        self.assertRaises(ValueError, buffer.fromhex, 'rt')
-        self.assertRaises(ValueError, buffer.fromhex, '1a b cd')
-        self.assertRaises(ValueError, buffer.fromhex, '\x00')
-        self.assertRaises(ValueError, buffer.fromhex, '12   \x00   34')
+        self.assertRaises(TypeError, bytearray.fromhex)
+        self.assertRaises(TypeError, bytearray.fromhex, 1)
+        self.assertEquals(bytearray.fromhex(''), bytearray())
+        b = bytearray([0x1a, 0x2b, 0x30])
+        self.assertEquals(bytearray.fromhex('1a2B30'), b)
+        self.assertEquals(bytearray.fromhex('  1A 2B  30   '), b)
+        self.assertEquals(bytearray.fromhex('0000'), b'\0\0')
+        self.assertRaises(TypeError, bytearray.fromhex, b'1B')
+        self.assertRaises(ValueError, bytearray.fromhex, 'a')
+        self.assertRaises(ValueError, bytearray.fromhex, 'rt')
+        self.assertRaises(ValueError, bytearray.fromhex, '1a b cd')
+        self.assertRaises(ValueError, bytearray.fromhex, '\x00')
+        self.assertRaises(ValueError, bytearray.fromhex, '12   \x00   34')
 
     def test_join(self):
         self.assertEqual(b"".join([]), b"")
@@ -518,20 +518,20 @@
             (br"\xaa\x00\000\200", r"\xaa\x00\000\200"),
         ]
         for b, s in tests:
-            self.assertEqual(b, buffer(s, 'latin-1'))
+            self.assertEqual(b, bytearray(s, 'latin-1'))
         for c in range(128, 256):
             self.assertRaises(SyntaxError, eval,
                               'b"%s"' % chr(c))
 
     def test_extend(self):
         orig = b'hello'
-        a = buffer(orig)
+        a = bytearray(orig)
         a.extend(a)
         self.assertEqual(a, orig + orig)
         self.assertEqual(a[5:], orig)
 
     def test_remove(self):
-        b = buffer(b'hello')
+        b = bytearray(b'hello')
         b.remove(ord('l'))
         self.assertEqual(b, b'helo')
         b.remove(ord('l'))
@@ -546,15 +546,15 @@
         self.assertRaises(TypeError, lambda: b.remove(b'e'))
 
     def test_pop(self):
-        b = buffer(b'world')
+        b = bytearray(b'world')
         self.assertEqual(b.pop(), ord('d'))
         self.assertEqual(b.pop(0), ord('w'))
         self.assertEqual(b.pop(-2), ord('r'))
         self.assertRaises(IndexError, lambda: b.pop(10))
-        self.assertRaises(OverflowError, lambda: buffer().pop())
+        self.assertRaises(OverflowError, lambda: bytearray().pop())
 
     def test_nosort(self):
-        self.assertRaises(AttributeError, lambda: buffer().sort())
+        self.assertRaises(AttributeError, lambda: bytearray().sort())
 
     def test_index(self):
         b = b'parrot'
@@ -570,17 +570,17 @@
         self.assertEqual(b.count(b'w'), 0)
 
     def test_append(self):
-        b = buffer(b'hell')
+        b = bytearray(b'hell')
         b.append(ord('o'))
         self.assertEqual(b, b'hello')
         self.assertEqual(b.append(100), None)
-        b = buffer()
+        b = bytearray()
         b.append(ord('A'))
         self.assertEqual(len(b), 1)
         self.assertRaises(TypeError, lambda: b.append(b'o'))
 
     def test_insert(self):
-        b = buffer(b'msssspp')
+        b = bytearray(b'msssspp')
         b.insert(1, ord('i'))
         b.insert(4, ord('i'))
         b.insert(-2, ord('i'))
@@ -590,7 +590,7 @@
 
     def test_startswith(self):
         b = b'hello'
-        self.assertFalse(buffer().startswith(b"anything"))
+        self.assertFalse(bytearray().startswith(b"anything"))
         self.assertTrue(b.startswith(b"hello"))
         self.assertTrue(b.startswith(b"hel"))
         self.assertTrue(b.startswith(b"h"))
@@ -599,7 +599,7 @@
 
     def test_endswith(self):
         b = b'hello'
-        self.assertFalse(buffer().endswith(b"anything"))
+        self.assertFalse(bytearray().endswith(b"anything"))
         self.assertTrue(b.endswith(b"hello"))
         self.assertTrue(b.endswith(b"llo"))
         self.assertTrue(b.endswith(b"o"))
@@ -645,7 +645,7 @@
 
     def test_translate(self):
         b = b'hello'
-        rosetta = buffer(range(0, 256))
+        rosetta = bytearray(range(0, 256))
         rosetta[ord('o')] = ord('e')
         c = b.translate(rosetta, b'l')
         self.assertEqual(b, b'hello')
@@ -668,7 +668,7 @@
         self.assertEqual(b'  a  bb  c  '.split(None, 2), [b'a', b'bb', b'c  '])
         self.assertEqual(b'  a  bb  c  '.split(None, 3), [b'a', b'bb', b'c'])
 
-    def test_split_buffer(self):
+    def test_split_bytearray(self):
         self.assertEqual(b'a b'.split(memoryview(b' ')), [b'a', b'b'])
 
     def test_split_string_error(self):
@@ -691,7 +691,7 @@
         self.assertEqual(b'  a  bb  c  '.rsplit(None,2), [b'  a', b'bb', b'c'])
         self.assertEqual(b'  a  bb  c  '.rsplit(None, 3), [b'a', b'bb', b'c'])
 
-    def test_rsplit_buffer(self):
+    def test_rsplit_bytearray(self):
         self.assertEqual(b'a b'.rsplit(memoryview(b' ')), [b'a', b'b'])
 
     def test_rsplit_string_error(self):
@@ -745,7 +745,7 @@
         self.assertEqual(b.lstrip(), b'abc \t\n\r\f\v')
         self.assertEqual(b.rstrip(), b' \t\n\r\f\vabc')
 
-    def test_strip_buffer(self):
+    def test_strip_bytearray(self):
         self.assertEqual(b'abc'.strip(memoryview(b'ac')), b'b')
         self.assertEqual(b'abc'.lstrip(memoryview(b'ac')), b'bc')
         self.assertEqual(b'abc'.rstrip(memoryview(b'ac')), b'ab')
@@ -760,24 +760,24 @@
         self.assertEqual([ord(b[i:i+1]) for i in range(len(b))],
                          [0, 65, 127, 128, 255])
 
-    def test_partition_buffer_doesnt_share_nullstring(self):
-        a, b, c = buffer(b"x").partition(b"y")
+    def test_partition_bytearray_doesnt_share_nullstring(self):
+        a, b, c = bytearray(b"x").partition(b"y")
         self.assertEqual(b, b"")
         self.assertEqual(c, b"")
         self.assert_(b is not c)
         b += b"!"
         self.assertEqual(c, b"")
-        a, b, c = buffer(b"x").partition(b"y")
+        a, b, c = bytearray(b"x").partition(b"y")
         self.assertEqual(b, b"")
         self.assertEqual(c, b"")
         # Same for rpartition
-        b, c, a = buffer(b"x").rpartition(b"y")
+        b, c, a = bytearray(b"x").rpartition(b"y")
         self.assertEqual(b, b"")
         self.assertEqual(c, b"")
         self.assert_(b is not c)
         b += b"!"
         self.assertEqual(c, b"")
-        c, b, a = buffer(b"x").rpartition(b"y")
+        c, b, a = bytearray(b"x").rpartition(b"y")
         self.assertEqual(b, b"")
         self.assertEqual(c, b"")
 
@@ -793,22 +793,22 @@
     # Unfortunately they are all bundled with tests that
     # are not appropriate for bytes
 
-    # I've started porting some of those into buffer_tests.py, we should port
+    # I've started porting some of those into bytearray_tests.py, we should port
     # the rest that make sense (the code can be cleaned up to use modern
     # unittest methods at the same time).
 
-class BufferPEP3137Test(unittest.TestCase,
+class BytearrayPEP3137Test(unittest.TestCase,
                        test.buffer_tests.MixinBytesBufferCommonTests):
     def marshal(self, x):
-        return buffer(x)
+        return bytearray(x)
         # TODO this should become:
-        #return buffer(x)
-        # once the bytes -> buffer and str8 -> bytes rename happens
+        #return bytearray(x)
+        # once the bytes -> bytearray and str8 -> bytes rename happens
 
     def test_returns_new_copy(self):
         val = self.marshal(b'1234')
         # On immutable types these MAY return a reference to themselves
-        # but on mutable types like buffer they MUST return a new copy.
+        # but on mutable types like bytearray they MUST return a new copy.
         for methname in ('zfill', 'rjust', 'ljust', 'center'):
             method = getattr(val, methname)
             newval = method(3)
@@ -818,7 +818,7 @@
 
 
 class BytesAsStringTest(test.string_tests.BaseTest):
-    type2test = buffer
+    type2test = bytearray
 
     def fixtype(self, obj):
         if isinstance(obj, str):
@@ -838,17 +838,17 @@
         pass
 
 
-class BufferSubclass(buffer):
+class ByteArraySubclass(bytearray):
     pass
 
-class BufferSubclassTest(unittest.TestCase):
+class ByteArraySubclassTest(unittest.TestCase):
 
     def test_basic(self):
-        self.assert_(issubclass(BufferSubclass, buffer))
-        self.assert_(isinstance(BufferSubclass(), buffer))
+        self.assert_(issubclass(ByteArraySubclass, bytearray))
+        self.assert_(isinstance(ByteArraySubclass(), bytearray))
 
         a, b = b"abcd", b"efgh"
-        _a, _b = BufferSubclass(a), BufferSubclass(b)
+        _a, _b = ByteArraySubclass(a), ByteArraySubclass(b)
 
         # test comparison operators with subclass instances
         self.assert_(_a == _a)
@@ -871,19 +871,19 @@
         # Make sure join returns a NEW object for single item sequences
         # involving a subclass.
         # Make sure that it is of the appropriate type.
-        s1 = BufferSubclass(b"abcd")
-        s2 = buffer().join([s1])
+        s1 = ByteArraySubclass(b"abcd")
+        s2 = bytearray().join([s1])
         self.assert_(s1 is not s2)
-        self.assert_(type(s2) is buffer, type(s2))
+        self.assert_(type(s2) is bytearray, type(s2))
 
         # Test reverse, calling join on subclass
         s3 = s1.join([b"abcd"])
-        self.assert_(type(s3) is buffer)
+        self.assert_(type(s3) is bytearray)
 
     def test_pickle(self):
-        a = BufferSubclass(b"abcd")
+        a = ByteArraySubclass(b"abcd")
         a.x = 10
-        a.y = BufferSubclass(b"efgh")
+        a.y = ByteArraySubclass(b"efgh")
         for proto in range(pickle.HIGHEST_PROTOCOL):
             b = pickle.loads(pickle.dumps(a, proto))
             self.assertNotEqual(id(a), id(b))
@@ -894,9 +894,9 @@
             self.assertEqual(type(a.y), type(b.y))
 
     def test_copy(self):
-        a = BufferSubclass(b"abcd")
+        a = ByteArraySubclass(b"abcd")
         a.x = 10
-        a.y = BufferSubclass(b"efgh")
+        a.y = ByteArraySubclass(b"efgh")
         for copy_method in (copy.copy, copy.deepcopy):
             b = copy_method(a)
             self.assertNotEqual(id(a), id(b))
@@ -907,9 +907,9 @@
             self.assertEqual(type(a.y), type(b.y))
 
     def test_init_override(self):
-        class subclass(buffer):
+        class subclass(bytearray):
             def __init__(self, newarg=1, *args, **kwargs):
-                buffer.__init__(self, *args, **kwargs)
+                bytearray.__init__(self, *args, **kwargs)
         x = subclass(4, source=b"abcd")
         self.assertEqual(x, b"abcd")
         x = subclass(newarg=4, source=b"abcd")
@@ -919,8 +919,8 @@
 def test_main():
     test.test_support.run_unittest(BytesTest)
     test.test_support.run_unittest(BytesAsStringTest)
-    test.test_support.run_unittest(BufferSubclassTest)
-    test.test_support.run_unittest(BufferPEP3137Test)
+    test.test_support.run_unittest(ByteArraySubclassTest)
+    test.test_support.run_unittest(BytearrayPEP3137Test)
 
 if __name__ == "__main__":
     test_main()
diff --git a/Lib/test/test_codeccallbacks.py b/Lib/test/test_codeccallbacks.py
index 218bfc5..12eb068 100644
--- a/Lib/test/test_codeccallbacks.py
+++ b/Lib/test/test_codeccallbacks.py
@@ -33,13 +33,13 @@
 # A UnicodeDecodeError object without an end attribute
 class NoEndUnicodeDecodeError(UnicodeDecodeError):
     def __init__(self):
-        UnicodeDecodeError.__init__(self, "ascii", buffer(b""), 0, 1, "bad")
+        UnicodeDecodeError.__init__(self, "ascii", bytearray(b""), 0, 1, "bad")
         del self.end
 
 # A UnicodeDecodeError object with a bad object attribute
 class BadObjectUnicodeDecodeError(UnicodeDecodeError):
     def __init__(self):
-        UnicodeDecodeError.__init__(self, "ascii", buffer(b""), 0, 1, "bad")
+        UnicodeDecodeError.__init__(self, "ascii", bytearray(b""), 0, 1, "bad")
         self.object = []
 
 # A UnicodeTranslateError object without a start attribute
@@ -363,12 +363,12 @@
     def test_unicodedecodeerror(self):
         self.check_exceptionobjectargs(
             UnicodeDecodeError,
-            ["ascii", buffer(b"g\xfcrk"), 1, 2, "ouch"],
+            ["ascii", bytearray(b"g\xfcrk"), 1, 2, "ouch"],
             "'ascii' codec can't decode byte 0xfc in position 1: ouch"
         )
         self.check_exceptionobjectargs(
             UnicodeDecodeError,
-            ["ascii", buffer(b"g\xfcrk"), 1, 3, "ouch"],
+            ["ascii", bytearray(b"g\xfcrk"), 1, 3, "ouch"],
             "'ascii' codec can't decode bytes in position 1-2: ouch"
         )
 
@@ -442,7 +442,7 @@
         )
         self.assertEquals(
             codecs.ignore_errors(
-                UnicodeDecodeError("ascii", buffer(b"\xff"), 0, 1, "ouch")),
+                UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")),
             ("", 1)
         )
         self.assertEquals(
@@ -482,7 +482,7 @@
         )
         self.assertEquals(
             codecs.replace_errors(
-                UnicodeDecodeError("ascii", buffer(b"\xff"), 0, 1, "ouch")),
+                UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")),
             ("\ufffd", 1)
         )
         self.assertEquals(
@@ -508,7 +508,7 @@
         self.assertRaises(
             TypeError,
             codecs.xmlcharrefreplace_errors,
-            UnicodeDecodeError("ascii", buffer(b"\xff"), 0, 1, "ouch")
+            UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")
         )
         self.assertRaises(
             TypeError,
@@ -542,7 +542,7 @@
         self.assertRaises(
             TypeError,
             codecs.backslashreplace_errors,
-            UnicodeDecodeError("ascii", buffer(b"\xff"), 0, 1, "ouch")
+            UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")
         )
         self.assertRaises(
             TypeError,
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
index 0243134..3ccc06c 100644
--- a/Lib/test/test_collections.py
+++ b/Lib/test/test_collections.py
@@ -99,7 +99,7 @@
 
     def test_Hashable(self):
         # Check some non-hashables
-        non_samples = [buffer(), list(), set(), dict()]
+        non_samples = [bytearray(), list(), set(), dict()]
         for x in non_samples:
             self.failIf(isinstance(x, Hashable), repr(x))
             self.failIf(issubclass(type(x), Hashable), repr(type(x)))
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index 6e5b990..7c08f9e 100644
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -1093,7 +1093,7 @@
             self.assertEqual(orig, derived)
 
     def test_backdoor_resistance(self):
-        # For fast unpickling, the constructor accepts a pickle string.
+        # For fast unpickling, the constructor accepts a pickle byte string.
         # This is a low-overhead backdoor.  A user can (by intent or
         # mistake) pass a string directly, which (if it's the right length)
         # will get treated like a pickle, and bypass the normal sanity
@@ -1101,17 +1101,17 @@
         # The constructor doesn't want to burn the time to validate all
         # fields, but does check the month field.  This stops, e.g.,
         # datetime.datetime('1995-03-25') from yielding an insane object.
-        base = '1995-03-25'
+        base = b'1995-03-25'
         if not issubclass(self.theclass, datetime):
             base = base[:4]
-        for month_byte in '9', chr(0), chr(13), '\xff':
+        for month_byte in b'9', b'\0', b'\r', b'\xff':
             self.assertRaises(TypeError, self.theclass,
                                          base[:2] + month_byte + base[3:])
         for ord_byte in range(1, 13):
             # This shouldn't blow up because of the month byte alone.  If
             # the implementation changes to do more-careful checking, it may
             # blow up because other fields are insane.
-            self.theclass(buffer(base[:2] + chr(ord_byte) + base[3:], "ascii"))
+            self.theclass(base[:2] + bytes([ord_byte]) + base[3:])
 
 #############################################################################
 # datetime tests
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index c405ac9..d1f9b1a 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -253,9 +253,9 @@
                                            'ordinal not in range'),
                  'encoding' : 'ascii', 'object' : 'a',
                  'start' : 0, 'reason' : 'ordinal not in range'}),
-            (UnicodeDecodeError, ('ascii', buffer(b'\xff'), 0, 1,
+            (UnicodeDecodeError, ('ascii', bytearray(b'\xff'), 0, 1,
                                   'ordinal not in range'),
-                {'args' : ('ascii', buffer(b'\xff'), 0, 1,
+                {'args' : ('ascii', bytearray(b'\xff'), 0, 1,
                                            'ordinal not in range'),
                  'encoding' : 'ascii', 'object' : b'\xff',
                  'start' : 0, 'reason' : 'ordinal not in range'}),
diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
index ca5e537..4360c54 100644
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -40,14 +40,14 @@
                           'chicken', 'unknown')
 
 BE_DOUBLE_INF = b'\x7f\xf0\x00\x00\x00\x00\x00\x00'
-LE_DOUBLE_INF = bytes(reversed(buffer(BE_DOUBLE_INF)))
+LE_DOUBLE_INF = bytes(reversed(BE_DOUBLE_INF))
 BE_DOUBLE_NAN = b'\x7f\xf8\x00\x00\x00\x00\x00\x00'
-LE_DOUBLE_NAN = bytes(reversed(buffer(BE_DOUBLE_NAN)))
+LE_DOUBLE_NAN = bytes(reversed(BE_DOUBLE_NAN))
 
 BE_FLOAT_INF = b'\x7f\x80\x00\x00'
-LE_FLOAT_INF = bytes(reversed(buffer(BE_FLOAT_INF)))
+LE_FLOAT_INF = bytes(reversed(BE_FLOAT_INF))
 BE_FLOAT_NAN = b'\x7f\xc0\x00\x00'
-LE_FLOAT_NAN = bytes(reversed(buffer(BE_FLOAT_NAN)))
+LE_FLOAT_NAN = bytes(reversed(BE_FLOAT_NAN))
 
 # on non-IEEE platforms, attempting to unpack a bit pattern
 # representing an infinity or a NaN should raise an exception.
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 697f69e..7ca3fbb 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -88,7 +88,7 @@
         self.assertEqual(f.tell(), 6)
         self.assertEqual(f.seek(-1, 1), 5)
         self.assertEqual(f.tell(), 5)
-        self.assertEqual(f.write(buffer(b" world\n\n\n")), 9)
+        self.assertEqual(f.write(bytearray(b" world\n\n\n")), 9)
         self.assertEqual(f.seek(0), 0)
         self.assertEqual(f.write(b"h"), 1)
         self.assertEqual(f.seek(-1, 2), 13)
@@ -100,7 +100,7 @@
     def read_ops(self, f, buffered=False):
         data = f.read(5)
         self.assertEqual(data, b"hello")
-        data = buffer(data)
+        data = bytearray(data)
         self.assertEqual(f.readinto(data), 5)
         self.assertEqual(data, b" worl")
         self.assertEqual(f.readinto(data), 2)
@@ -109,11 +109,11 @@
         self.assertEqual(f.seek(0), 0)
         self.assertEqual(f.read(20), b"hello world\n")
         self.assertEqual(f.read(1), b"")
-        self.assertEqual(f.readinto(buffer(b"x")), 0)
+        self.assertEqual(f.readinto(bytearray(b"x")), 0)
         self.assertEqual(f.seek(-6, 2), 6)
         self.assertEqual(f.read(5), b"world")
         self.assertEqual(f.read(0), b"")
-        self.assertEqual(f.readinto(buffer()), 0)
+        self.assertEqual(f.readinto(bytearray()), 0)
         self.assertEqual(f.seek(-6, 1), 5)
         self.assertEqual(f.read(5), b" worl")
         self.assertEqual(f.tell(), 10)
diff --git a/Lib/test/test_marshal.py b/Lib/test/test_marshal.py
index fb70ced..d14d50d 100644
--- a/Lib/test/test_marshal.py
+++ b/Lib/test/test_marshal.py
@@ -39,7 +39,7 @@
         # we're running the test on a 32-bit box, of course.
 
         def to_little_endian_string(value, nbytes):
-            b = buffer()
+            b = bytearray()
             for i in range(nbytes):
                 b.append(value & 0xff)
                 value >>= 8
diff --git a/Lib/test/test_struct.py b/Lib/test/test_struct.py
index db6a97d..34596e0 100644
--- a/Lib/test/test_struct.py
+++ b/Lib/test/test_struct.py
@@ -560,11 +560,11 @@
     test_string = b'abcd01234'
     fmt = '4s'
     s = struct.Struct(fmt)
-    for cls in (buffer, bytes):
+    for cls in (bytes, bytearray):
         if verbose:
             print("test_unpack_from using", cls.__name__)
         data = cls(test_string)
-        if not isinstance(data, (buffer, bytes)):
+        if not isinstance(data, (bytes, bytearray)):
             bytes_data = bytes(data, 'latin1')
         else:
             bytes_data = data
@@ -575,7 +575,7 @@
             vereq(s.unpack_from(data, i), (bytes_data[i:i+4],))
         for i in range(6, len(test_string) + 1):
             simple_err(s.unpack_from, data, i)
-    for cls in (buffer, bytes):
+    for cls in (bytes, bytearray):
         data = cls(test_string)
         vereq(struct.unpack_from(fmt, data), (b'abcd',))
         vereq(struct.unpack_from(fmt, data, 2), (b'cd01',))
diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
index d53317f..7475535 100644
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -218,8 +218,8 @@
         warnings.simplefilter('ignore', BytesWarning)
         self.assertEqual('abc' == b'abc', False)
         self.assertEqual('abc' != b'abc', True)
-        self.assertEqual('abc' == buffer(b'abc'), False)
-        self.assertEqual('abc' != buffer(b'abc'), True)
+        self.assertEqual('abc' == bytearray(b'abc'), False)
+        self.assertEqual('abc' != bytearray(b'abc'), True)
 
     def test_comparison(self):
         # Comparisons:
diff --git a/Lib/test/test_unicodedata.py b/Lib/test/test_unicodedata.py
index ba97e5d..c4ea816 100644
--- a/Lib/test/test_unicodedata.py
+++ b/Lib/test/test_unicodedata.py
@@ -177,7 +177,7 @@
     def test_east_asian_width(self):
         eaw = self.db.east_asian_width
         self.assertRaises(TypeError, eaw, b'a')
-        self.assertRaises(TypeError, eaw, buffer())
+        self.assertRaises(TypeError, eaw, bytearray())
         self.assertRaises(TypeError, eaw, '')
         self.assertRaises(TypeError, eaw, 'ra')
         self.assertEqual(eaw('\x1e'), 'N')
diff --git a/Lib/test/test_zipimport.py b/Lib/test/test_zipimport.py
index cb20222..4019440 100644
--- a/Lib/test/test_zipimport.py
+++ b/Lib/test/test_zipimport.py
@@ -153,7 +153,7 @@
 
     def testBadMagic(self):
         # make pyc magic word invalid, forcing loading from .py
-        badmagic_pyc = buffer(test_pyc)
+        badmagic_pyc = bytearray(test_pyc)
         badmagic_pyc[0] ^= 0x04  # flip an arbitrary bit
         files = {TESTMOD + ".py": (NOW, test_src),
                  TESTMOD + pyc_ext: (NOW, badmagic_pyc)}
@@ -161,7 +161,7 @@
 
     def testBadMagic2(self):
         # make pyc magic word invalid, causing an ImportError
-        badmagic_pyc = buffer(test_pyc)
+        badmagic_pyc = bytearray(test_pyc)
         badmagic_pyc[0] ^= 0x04  # flip an arbitrary bit
         files = {TESTMOD + pyc_ext: (NOW, badmagic_pyc)}
         try:
@@ -172,7 +172,7 @@
             self.fail("expected ImportError; import from bad pyc")
 
     def testBadMTime(self):
-        badtime_pyc = buffer(test_pyc)
+        badtime_pyc = bytearray(test_pyc)
         badtime_pyc[7] ^= 0x02  # flip the second bit -- not the first as that one
                                 # isn't stored in the .py's mtime in the zip archive.
         files = {TESTMOD + ".py": (NOW, test_src),
diff --git a/Lib/uuid.py b/Lib/uuid.py
index 06115c7..eaf7c88 100644
--- a/Lib/uuid.py
+++ b/Lib/uuid.py
@@ -234,7 +234,7 @@
 
     @property
     def bytes(self):
-        bytes = buffer()
+        bytes = bytearray()
         for shift in range(0, 128, 8):
             bytes.insert(0, (self.int >> shift) & 0xff)
         return bytes